How do you calculate a percentage?

Like 15 percent of 100 and 20 percent of 200.



I can't remember how to do them.How do you calculate a percentage?
take percent - divide by 100



So now you have .15 instead of 15%. Now multiply to .15 by whatever you want to find it of.



so 15% of a 100 = .15 x 100 = 15



20% of 200 = .20 x 200 = 40